Wind signatures in the X-ray emission line profiles of the late O supergiant $ζ$ Orionis

Simple item page
dc.creatorCohen, David H.
dc.creatorLeutenegger, Maurice A.
dc.creatorGrizzard, Kevin T.
dc.creatorReed, Catherine L.
dc.creatorKramer, Roban H.
dc.creatorOwocki, Stanley P.
dc.date2006-02-27
dc.date2006-03-27
dc.date.accessioned2026-07-07T10:27:57Z
dc.date.available2026-07-07T10:27:57Z
dc.descriptionX-ray line profile analysis has proved to be the most direct diagnostic of the kinematics and spatial distribution of the very hot plasma around O stars. In this paper we apply several analysis techniques to the emission lines in the Chandra HETGS spectrum of the late-O supergiant zeta Ori (O9.7 Ib), including the fitting of a simple line-profile model. We show that there is distinct evidence for blue shifts and profile asymmetry, as well as broadening in the X-ray emission lines of zeta Ori. These are the observational hallmarks of a wind-shock X-ray source, and the results for zeta Ori are very similar to those for the earlier O star, zeta Pup, which we have previously shown to be well-fit by the same wind-shock line-profile model. The more subtle effects on the line-profile morphologies in zeta Ori, as compared to zeta Pup, are consistent with the somewhat lower density wind in this later O supergiant. In both stars, the wind optical depths required to explain the mildly asymmetric X-ray line profiles imply reductions in the effective opacity of nearly an order of magnitude, which may be explained by some combination of mass-loss rate reduction and large-scale clumping, with its associated porosity-based effects on radiation transfer. In the context of the recent reanalysis of the helium-like line intensity ratios in both zeta Ori and zeta Pup, and also in light of recent work questioning the published mass-loss rates in OB stars, these new results indicate that the X-ray emission from zeta Ori can be understood within the framework of the standard wind-shock scenario for hot stars.
dc.descriptionMNRAS, accepted; 16 pages, 5 figures
dc.identifierhttps://arxiv.org/abs/astro-ph/0602599
dc.identifierhttp://arxiv.org/abs/astro-ph/0602599
dc.identifierMon.Not.Roy.Astron.Soc.368:1905-1916,2006
dc.identifierdoi:10.1111/j.1365-2966.2006.10259.x
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/177285
dc.subjectAstrophysics
dc.titleWind signatures in the X-ray emission line profiles of the late O supergiant $ζ$ Orionis
dc.typetext

Files

Collections

arXiv